Modern sausage making machines extrude meat emulsion into an elongated hollow casing to create a sausage strand. These machines divide the strand into a plurality of links, and the linked strand is then deposited on a conveyor for final disposition. The sausage casings have finite lengths, so the machines have to be stopped each time a given casing has been filled. When a casing breaks, the machine is stopped to replace the casing, and to avoid wastage of meat emulsion. Further, the uniformity or consistent geometry of the filled casings are not easily monitored. All of the above problems are greater when natural rather than artificial casings are used.
It is therefore a principal object of this invention to provide a method and apparatus for controlling the operation of a sausage making machine by way of a sensor and a PLC which is automatic and continuous, and which can stop the machine instantly whenever any irregular production of sausages is sensed, including running out of casing material, casing breakage, or improperly filled casings.
It is still a further object of the invention to have the sensing means flexible enough in its character in order to take into account varying product diameters and modes of operation of the sausage encasing machine.
It is a further object of this invention to have a sensing means that will scan the encased sausage strand and communicate to a PLC in such a way as to ignore the twists in the casing which separate the sausages or protruding parts of the linker and not stop the machine unless there is a sustained drop in diameter.
These and other objects will be apparent to those skilled in the art.
The apparatus of the present invention is an improvement on a conventional sausage encasing machine that includes a frame, a meat emulsion pump, an elongated stuffing tube operatively connected to the pump for receiving meat emulsion therefrom and being adapted to slidably receive an elongated hollow sausage casing on an outer surface thereof, a twisting assembly adapted to receive and rotate a casing on the tube when the tube is moved into operative engagement therewith, a casing linking assembly on the frame downstream of the twister assembly to link the casing filled with meat emulsion, and power means on the frame for operating the pump, the twisting assembly, and the linker assembly. A computer is mounted on the frame, a casing diameter sensor is located on the frame and is located downstream of an exit end of the tube to sense the height of the casing downstream of the exit end of the tube. The sensor is operatively connected to the computer to transmit data to the computer as to the height of the top surface of the casing or meat strand being scanned. The computer is programmed to retain predetermined or position parameters for a range of acceptable casing sizes. The computer is also programmed to signal the power means to cease operation whenever the computer detects that the sensed casing diameter is beyond the predetermined diameter parameters.
The sensor is intended to sense the presence of an unacceptable sausage or meat strand size. The sensor can do this by detecting a casing of unusual diameter, for example, or by detecting the location or position of the upper surface of the casing or meat strand which would indicate a broken casing, for example. In such case, the upper surface of the casing would be at an abnormally lower or higher height.
The method of the invention involves placing an elongated hollow sausage casing on the tube so that meat emulsion exiting the tube will fill the casing; providing operational power to the pump; the twisting assembly; and the linking assembly; extending the tube through the linking assembly so that an exit end thereof terminates adjacent the linking assembly; sensing the outer diameter of the casing downstream from the exit end of the tube; comparing the sensed diameter of the casing with predetermined diameter parameters for a range of acceptable casing diameters; transferring the data from the sensor as to the measured diameter of the casing to a computer; and causing the computer to stop the operation of the machine if the measured diameter is outside the predetermined diameter parameters.
More specifically, in order to remove the difficulty of broken casings and/or the end of casings the invention determines the net distance of the surface of the casing from the sensor. This information is gathered by a sensor, which may be ultrasonic, optical, or mechanical. The information is transmitted to the programmable logic controller which interprets the signal and determines whether to shut off the emulsion pump.
The beginning of each strand of casing is smaller so there is a delay of, for example, 100 m sec to give the casing time to reach its appropriate diameter.
Since the conveying pinchers and twist-inducing butterflies are also entering the field of the scanning device, the readings are processed, for example, averaged every 10 m sec. This window allows the twisted portions of product to go through without telling the PLC that the diameter has fallen below the minimum acceptable for the pumping of emulsion. If averaging data is used, the averaging can be done by the sensor or the PLC. If averaging is not used, then the sensitivity of the sensor may be adjusted to eliminate false readings of bad casings when twists pass the target window.